Observations on the coronary arteries of 100 embalmed hearts from 56 adults and 44 children, have been made. The results are as follows: (1) The point of origin of coronary arteries was found vertically on the margin of the aortic sinus in 69.4% of the left and 52.8% of the right respectively and horizontally at the middle third of the aortic sinus in 79.7% of the left and 67.5% of the right respectively. (2) The external diameter at the opening of the left coronary artery is greater than the right in both adults and children. The mean value of the external diameter at the opening of the left coronary arteries was 0.41?0.14 cm and of the right 0.31?0.02 cm, in children, while in adult, the figures were 0.53?0.02 cm and 0.45?0.02 cm respectively. (3) The accessory coronary artery occurred in 10%.The percentage is lower than other reports in China. (4) The branch and distribution of the left coronary artery were studied thoroughly; its diagonal branch occurred in 38.4%.The mean value of the angle between the left anterior descending branch and the left circumflex artery was about 80?. In one the left circumflex artery was absent. (5) The branch and distribution of the right coronary artery were also investigated carefully. Fifty six percent of the right coronary arteries terminate in the heart, diaphragmatic surface between the crux of the heart and the obtuse margin. The posterior descending branch of right coronary artery ended in the middle-lower third of the posterior longitudinal sulcus of the heart. The occurrence of desending septum artery is 6.1%. (6) An investigation on the posterior superior septum artery and Kugel’s artery has been made: the former, 45.5% of which originated from the right coronary artery, possessed only one branch while the latter, which has been seen in three cases, occurred in 30%. (7) The common type of distribution, in which the posterior wall of the left ventricle was supplied by the right circumflex branch, occurred in 80.2%.